License requirements for commercial program [closed]

Question

This page summarizes different license types' terms (GPL, LGPL, MIT, BSD, etc): http://www.codeproject.com/info/Licenses.aspx

Say I write a program for sale that uses a software under one of the licensing types where "Can be used in commercial applications:" is true, and "Can be used in proprietary (closed source) applications:" is true.

Then if the "Bug fixes / extensions must be released to the public domain:" line is true, what does it mean to me? What am I required to do?

Thank you.

Answer 1

This will usually mean that if you build a patch or other modification of the program and want to distribute it you must also publish the sources of that modification under a license explicitly mentioned in the program license text.

In some license types this includes both the other program and any program using that (including your program). In others (like LGPL) this will only be required only for modification made to that program, but not to your program if they are separated (LGPL is typically used for libraries and doesn't enforce publishing the library consumers).